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Focal Functional Deficits in Temporal Lobe Epilepsy on PET Scans and the Intracarotid Amobarbital Procedure: Comparison of Patients with Unitemporal Epilepsy with Those Requiring Intracranial Recordings
Author(s) -
Salanova V.,
Markand O.,
Worth R.
Publication year - 2001
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1046/j.1528-1157.2001.17200.x
Subject(s) - hippocampal sclerosis , temporal lobe , epilepsy , amobarbital , magnetic resonance imaging , tuberous sclerosis , medicine , positron emission tomography , electroencephalography , epilepsy surgery , nuclear medicine , radiology , psychology , psychiatry
Summary: Purpose: To analyze the relationship between the intracarotid amobarbital procedure (IAP) and positron emission tomography (PET) and study the lateralizing value of these tests in patients with unitemporal epilepsy and those requiring intracranial recordings. Methods: We compared 51 patients with unitemporal epilepsy (group1) with 26 patients in whom surface recordings failed to reveal a distinct unitemporal focus, necessitating invasive recordings (group 2). Results: The brain magnetic resonance imaging (MRI) scans for group 1 showed mesial temporal sclerosis in 70.5% of the patients. PET showed unilateral temporal hypometabolism in 88%. In addition, 74.5% of the patients in group 1 had impaired memory on the epileptogenic side on the IAP, and 89.4% of those patients also had ipsilateral temporal hypometabolism on PET scans. All the group 1 patients underwent temporal resections. The pathologic examination showed hippocampal sclerosis in 72% of the patients. Eighty percent of group 1 patients became seizure free, and 16% had rare seizures (follow‐up, 2–7 years). MRIs for group 2 showed mesial temporal sclerosis in 31% of the patients; PET scans showed temporal hypometabolism in 39%. The IAP was lateralized in 47.8%. Sixty‐nine percent had temporal lobe resections. The pathologic examination showed hippocampal sclerosis in 44% of the patients. Forty‐four percent of group 2 patients became seizure free, and 27.7% had rare seizures (follow‐up, 2–8 years). Conclusions: Ninety‐six percent of the patients with unitemporal foci had focal functional deficits on the epileptogenic side on 18‐fluorodeoxyglucose‐(FDG) PET scans, the IAP, or both. The results of the FDG‐PET were predictive of impaired memory on the IAP. Memory impairment contralateral to the temporal hypometabolism found on the PET scans was never seen. These patients had an excellent outcome. In contrast, <50% of the patients requiring intracranial recordings had focal functional deficits, suggesting that more a diffuse pathology may account for their less favorable outcome.